Heretofore, a solid-state imaging device takes measures such as enlarging pixels, for example, to realize highly sensitive image photography. If an image sensor becomes large due to enlargement of pixels, a distance (focal length) from an imaging lens to a light receiving surface becomes long, which makes thinning of the camera module difficult.
Most image sensors adopt a so-called Bayer arrangement in which a red (R) pixel and a blue (B) pixel are arranged at opposing corners of a 2×2 pixel block, and two green (G) pixels are arranged at the remaining opposing corners. An image sensor in which one G pixel of the 2×2 pixel block is replaced with a white (W) pixel to realize the highly sensitive image photography has been proposed. The W pixel retrieves white light. A signal charge amount of a luminance signal can be sufficiently ensured by arranging the W pixel.
The W pixel retrieves light of a wavelength region wider than that of other color pixels, and thus the saturation of the output with respect to an incident light quantity to a pixel cell occurs before other color pixels. The image sensor including the W pixel may not obtain a sufficient sensitivity for each color as the saturation of the output with respect to the incident light quantity occurs in the W pixel. Furthermore, a crosstalk that occurs when the light leaks from the W pixel to the other color pixels adjacent to the W pixel easily occurs as a great amount of light is retrieved to the W pixel. The image sensor including the W pixel has a problem in the lowering of color reproducibility by the crosstalk.
A phase difference detection method and a contrast detection method have been known for an autofocus function of the camera module. The autofocus by the contrast detection method has a problem that the focus adjustment takes time because the focusing is carried out while moving the imaging lens. The autofocus by the phase difference detection method has a problem that miniaturization of the camera module is difficult because a dedicated sensor of the autofocus and a configuration for branching light to the dedicated sensor are arranged.